Sown In Soil Research Articles

Response of African oil bean ( Pentaclethra Macrophylla Benth) seeds to soils contaminated with spent lubricating oil

This study evaluated the response (seedling emergence) of Pentaclethra macrophyllaseeds sown in soils contaminated with spent lubricating oil using 0, 1, 2, 4 and 8% w/w in Asaba, Delta State in 2009. The results showed that 100% of the seeds sown in the control germinated. Significant reductions (P ≥ 0.05) were however recorded in seeds planted in the soils treated with the spent lubricating oil. The effects being concentration dependent. The study has shown that spent lubricating oil has a highly significant (P ≤0.05) effect of reducing the germination percentage and rate of germination of P. macrophylla as well as increasing the days to germination of this multipurpose tree species. Key words: Influence, spent lubricating oil, seedly emergence, Pentaclethra macrophylla.

Efeito do protetor dietholate na seletividade de clomazone em cultivares de arroz irrigado

No arroz irrigado, o herbicida clomazone tem sua seletividade variável de acordo com o cultivar, o tipo de solo e a dose aplicada. O uso do protetor dietholate permite seletividade em diferentes ambientes, sendo necessário o estudo da relação entre esses fatores. Em vista do exposto, objetivou-se com este experimento quantificar a seletividade do herbicida clomazone em função de cultivares de arroz irrigado, tipos de solos, doses de clomazone e tratamento de sementes com dietholate. O experimento foi conduzido em casa de vegetação, em delineamento de blocos ao acaso, em esquema fatorial com quatro repetições. O fator A foi composto por tipos de solo (arenoso e argiloso); o fator B, por cultivares de arroz irrigado (IRGA 409 e IRGA 417); o fator C, pela ausência do protetor dietholate; e o fator D, por doses de clomazone (0, 156, 312, 625, 1.250, 2.500, 5.000 e 10.000 g ha-1) aplicadas em pré-emergência do arroz irrigado. Dezoito dias após a semeadura do arroz, foram avaliados a fitotoxicidade e o percentual de redução de massa fresca e seca da parte aérea das plantas de arroz. Os cultivares de arroz toleram maiores doses de clomazone quando tratados com dietholate e semeados em solos com maior teor de argila e matéria orgânica. Em solo arenoso, a toxicidade do herbicida nas plantas de arroz foi maior, na ordem de 50%, quando se comparou com a mesma dose em solo argiloso.

Impact of Conventional and Sustainable Soil Tillage and Sowing Technologies on Physical-Mechanical Soil Properties

Application of sustainable tillage and sowing technologies are rapidly increasing all over the world stimulating an interest in new technologies and their possibilities to reduce an impact of agricultural machinery on natural processes in Lithuania. This work aims to investigate the impact of different soil tillage and sowing technologies on physical-mechanical soil properties. Research was carried out in the periods of 2000-2002 and 2005-2007 in three Lithuanian districts with different soil properties: Kaunas, Marijampolė and Pasvalys. The interest was concentrated on the impact of conventional and sustainable soil tillage and sowing technologies on soil hardness, soil moisture and distribution of clods in the upper soil layers. The experimental studies have established that irrespective of soil heaviness, soil hardness in non-ploughed soils is greater than that after conventional ploughing. The increasing soil hardness changes the conditions for seed insertion into soil. Research results show that under Lithuanian conditions reduction in soil tillage intensity can save a considerably higher amount of soil moisture, which enables the improvement of seed germination. Analysis of clods distribution in the upper soil layers (< 15 mm) shows that the quantity of fine (< 2 mm) clods in non-ploughed soil is lower than that in the ploughed one which reduces the crust formation on the soil surface and the possible consequences of soil erosion.

Brassica Species as Winter Cover Crops in Sustainable Agricultural Systems in Southern Spain

The use of cover crops in orchards has increased in the last years in Mediterranean regions due to serious soil erosion problems. Brassicas show promising characteristics for erosion control such us rapid growth and production of abundant biomass, and also have a powerful root system, which helps to relieve soil compaction and to increase infiltration. The objective of this work was to select brassica species that are well adapted as cover crops to Mediterranean pedoclimatic conditions and to define the soil management practice and sowing depth for better emergence and establishment of the best-adapted species. To this aim ten wild and cultivated brassicas were evaluated in different soils during two growing season. Sinapis alba subsp. mairei and Eruca vesicaria had the highest coverage levels and were easily adapted to different soils showing they can be successfully used as cover crops in Mediterranean conditions.

Determination of linear alkylbenzenesulfonates (LASs) in sewage sludge and carrots by capillary electrophoresis–UV detection

A method based on capillary zone electrophoresis has been proposed in order to separate and determine four groups of linear alkylbenzenesulfonates in sewage sludge and carrots. The separation was carried out in a silica capillary of 50 cm × 75 µm at 25 kV using a sodium borate buffer solution of 100 mM which includes 40% of acetonitrile. The detection was made by UV–Vis diode array detector. Precision, accuracy, linearity, detection and quantification limits of the method were determined. Finally, the method was applied to analyse samples of sewage sludge from a wastewater depuration station in Crispijana (Alava, Spain) and carrots sown in soils spiked with this sludge. In this case, it is necessary to carry out an extraction step for its determination. The extraction was carried out by solid phase extraction with a C18 cartridge. The solid phase extraction (SPE) parameters were also optimized and the recoveries were calculated. Samples of sewage sludge were analysed weekly during two years and, in all cases, results under legal limits for their use in agriculture were obtained.

Effect of soil alkalinity and organic matter on seedling emergence and growth attributes of Anjan (Hardwickia binata Roxb.)

An experiment was conducted to find out the effect of different soil alkaline pH and organic matter on germination, seedling growth attributes and bio-chemical constituents of Hardwickia binata Roxb. The seeds were sown in soil with different pH (8.1, 9.0, 10.2 and 10.5) mixed with sand + farm yard manure (2:1:1 ratio) and compared with control (red earth + sand + farm yard manure at 2:1:1 ratio). Fourteen days after sowing it was found that the seeds sown in normal nursery soil (mixture of red earth + sand + farm yard manure) showed maximum germination (89.0%) and initial seedling vigour (1568), which was similar with seeds sown in soil with pH 10.2 + sand + farm yard manure. In 180 days old seedlings, the biometric and biochemical constituents recorded were higher in control treatment. From this experiment, it could be concluded that the Hardwickia binata seeds sown in higher soil pH along with sand and farm yard manure mixture showed good germination, seedling growth and biochemical constituents.

Bioremediation of sago industry effluent and its impact on seed germination (green gram and maize)

In this study, we attempted two investigational systems: one is treatment of sago industry effluent by aerobic bacterial consortium and the other is impact of treated and untreated effluent on seed germination. For the treatment system, the starch degrading bacteria were isolated from sago industry effluent and effluent contaminated soil. The genera, Alcaligenes, Bacillus and Corynebacterium were found efficient in starch degradation. The selected isolates were tested for their efficiency on the degradation of starch both in Mineral Salts Medium (MSM) and in sago industry effluent. About 85% of the starch was degraded in MSM by a bacterial consortium composed of Alcaligenes, Bacillus and Corynebacterium, whereas in effluent the degradation of starch was only 63%. The physico-chemical properties such as electrical conductivity, total solids, suspended solids, dissolved solids, BOD, COD, nitrogen and phosphate were found decreased in effluent after 72 h. The pH of the effluent was relatively increased from 3 to 6.7. The study of seed germination (maize and green gram) was carried out at 25, 50, 75 and 100% concentrations of treated and untreated effluent using soil sowing method. Shoot length, root length, fresh weight, dry weight and chlorophyll content showed an increase when treated effluent was tested whereas a decrease of growth was noticed in untreated effluent tested seedlings. The results revealed that effluent treated by aerobic microorganisms has no negative impact on the seed germination and can be effectively used for irrigation.

EFEITO RESIDUAL DO PREPARO DO SOLO E VELOCIDADE DE DESLOCAMENTO NA OPERAÇÃO DE SEMEADURA DA Crotalaria juncea

A operação de semeadura é muito importante para o estabelecimento das culturas, sendo responsável por significativa parcela do custo de produção de uma cultura. Assim, o objetivo do trabalho foi avaliar o desempenho de um trator agrícola sob dois sistemas de preparo do solo (sistema plantio direto e convencional), juntamente com três marchas na operação de semeadura da crotalária, que proporcionaram velocidades teóricas de 4, 5 e 7 km h-1. O experimento foi conduzido no campo experimental da UNESP de Jaboticabal, SP, Brasil, e conduzido pela equipe técnica do Laboratório de Máquinas e Mecanização Agrícola (LAMMA) em delineamento inteiramente casualizado com esquema fatorial 2 x 3 com quatro repetições. Foram mensurados: força de tração, potência na barra, capacidade de campo efetiva, consumo de energia, consumo horário de combustível, consumo efetivo, consumo ponderal e consumo especifico, como também a patinagem nos rodados do trator. Os resultados indicaram que não há diferença entre os sistemas de preparo do solo quanto aos parâmetros de desempenho do trator. Quanto à escolha da marcha, as velocidades maiores incrementam a potência, a capacidade de campo efetiva e o consumo horário, entretanto diminuem o tempo efetivo de trabalho por hectare, o consumo efetivo e o consumo específico.

Rhizoremediation of lindane by root‐colonizing Sphingomonas

SummaryWe used a two‐step enrichment approach to isolate root‐colonizing hexachlorocyclohexane (HCH)‐degrading microorganisms. The first step consists of the use of classical liquid enrichment to isolate γ‐HCH degraders. The γ‐HCH‐degrading microbes were attached in mass to corn seeds sown in soil with γ‐HCH, and after plant development we rescued bacteria growing on root tips. Bacteria were then subjected to a second enrichment round in which growth on liquid medium with γ‐HCH and inoculation of corn seeds were repeated. We then isolated bacteria on M9 minimal medium with γ‐HCH from root tips. We were able to isolate four Sphingomonas strains, all of which degraded α‐, β‐, γ‐ and δ‐HCH. Two of the strains were particularly good colonizers of corn roots, reaching high cell density in vegetated soil and partly removing γ‐HCH. In contrast, these bacteria performed poorly in unplanted soils. This study supports the hypothesis that the removal of persistent toxic chemicals can be accelerated by combinations of plants and bacteria, a process generally known as rhizoremediation.

Effects of soil moisture and sowing depth on the development of bean plants grown in sterile soil infested by Rhizoctonia solani and Trichoderma harzianum

The effects of soil moisture (varying from 15% to 42% (v/v)) and sowing depth (1.5–6.0 cm) on the development of bean plants grown in sterile soil infested by the pathogen Rhizoctonia solani and its antagonist Trichoderma harzianum were studied under greenhouse conditions. The four possible combinations of soil infestation with both fungi were tested. Disease severity, percentage of plants emerged, plant height and dry weight were evaluated 3 weeks after sowing. Emergence rate and growth of plants inoculated only with R. solani were not affected by soil moisture, but in the presence of both fungi, plant emergence, plant height and dry weight significantly decreased when soil moisture diminished. Deep sowing significantly reduced the emergence rate and growth of those plants that were inoculated with R. solani only. However, when the soil was infested with both fungi, the effect of sowing depth was not significant. At a sowing depth of 6.0 cm, the percentage of plants emerged was 50% in the presence of T. harzianum, but only 6.7% when the pathogen was inoculated alone. The antagonist protected bean seedlings from pre-emergence damping-off, reduced disease severity and increased plant growth in the presence of R. solani, especially in moist soil.

Avaliação de genótipos de milho para semeadura precoce sob influência de baixa temperatura

O milho (Zea mays L.) é uma planta de clima tropical que exige calor e umidade para produzir satisfatoriamente e proporcionar rendimentos compensadores. Diversos fatores podem comprometer a germinação das sementes e a emergência de plântulas no campo, merecendo destaque a semeadura em solos com baixas temperaturas. Em regiões que predominam condições de baixas temperaturas, seria importante o uso de sementes mais tolerantes a essa condição de estresse. Sementes de milho apresentam variabilidade genética para a germinação a baixas temperaturas. O objetivo deste trabalho foi classificar genótipos de milho quanto a tolerância das sementes à baixa temperatura de germinação, identificando àqueles com potencial para utilização em semeadura precoce. Avaliaram-se 16 genótipos provenientes do programa de melhoramento de milho da empresa KSP Sementes e Pesquisas Ltda., sendo 10 linhagens em diferentes estádios endogâmicos, seis populações de fecundação aberta e três híbridos simples comerciais, recomendados para semeadura precoce na Região Sul do Brasil. A avaliação da qualidade fisiológica das sementes foi feita pelos testes de germinação, primeira contagem de germinação, comprimento de plântula, biomassa seca, área foliar e radicular nas temperaturas de 25°C e 10°C. Foram realizadas análises eletroforéticas para os sistemas isoenzimáticos da fosfatase ácida, esterase e peroxidase. Os resultados permitiram classificar os genótipos quanto à tolerância das sementes à baixa temperatura, evidenciando que há variabilidade entre eles e potencialidades para serem usados em semeadura precoce na região sul do Brasil.

Heavy metal transfer from composted macroalgae to crops

Marine macroalgal compost may be used as fertiliser in agriculture and horticulture. However, macroalgae may accumulate heavy metals, thereby rendering compost made from it unsuitable for food crop production. Our aim was to determine whether the edible parts of crop plants grown in various macroalgal composts contain elevated concentrations of heavy metals. Compost of seaweed beach-cast containing up to 85% red macroalgae and experimentally produced red and brown-algal ( Fucus serratus) composts, respectively, were used in cultivating vegetables. The vegetables produced were compared with ones cultivated in composted horse manure and in soil in terms of transfer of cadmium (Cd), and in some cases also of copper (Cu), lead (Pb), and mercury (Hg) from the different substrates to the edible parts of the plants. Effects of the composted material on biomass production and seed germination were also examined. Concentrations of Cu, Hg, and Pb were not elevated in either of the composts or in the crop plants compared with limit values for cultivated plants and soil. However, the concentration of Cd in the composts and crop plants was greater than the limit values for arable soil and cultivated plants, respectively. Furthermore, more Cd was transferred to the plants grown in red-algal than in brown-algal ( F. serratus) compost, despite the fact that the brown-algal ( F. serratus) compost had a higher Cd concentration. The Cd concentrations in lettuce and oats cultivated in the seaweed composts exceeded official EU limit values, while the concentrations in root vegetables and leguminous plants were lower than the limit values. Cultivation in composted red macroalgae increased the biomass production of all vegetables except beans, compared with cultivation in the other substrates. However, the germination frequency was lower for seed sown in composted red and brown algae than for seed sown in soil. We conclude that although cultivation of food crops directly in composted macroalgae (specifically, composted red algae) would enhance yields, it is not recommended. Instead, macroalgal compost could be used in smaller amounts on agricultural soils as a valuable nutrient source for non-food crop cultivation.

Influences of soil tillage and fertilization on maize yield and weed infestation

The field experiment was conducted after wheat harvesting (July 1997) on Zemun Polje chernozem. Maize was grown under dry farming system (without irrigation) for three growing seasons (the factor A: 1998, 1999 and 2000). Soil tillage systems (the factor B) included three treatments as follows: B1) zero tillage (direct sowing in non-cultivated soil), B2) minimum tillage (tillage with a soil miller only and sowing) and B3) conventional tillage (stubble field shallow ploughing, ploughing in autumn, presowing soil preparing and sowing). In each soil tillage treatment three levels of fertilization were used as follows: C1) unfertilized (control), C2) the first level of fertilization (kg ha −1 : 150 N + 105 P 2 O 5 + 75 K 2 O) and C3) the second level of fertilization (kg ha −1 : 300 N + 211 P 2 O 5 + 150 K 2 O). The field experiment was conducted in four replicates. Area of base plot was 25 m 2 . Under drought stress of the 2000 growing season it was only 6.08 t ha −1 or 35% lower compared to 1999. The conventional tillage (yield 9.86 t ha −1 ) resulted by 24% and 84% yield increases compared to reduced tillage and zero-tillage, respectively. Using the second rate of fertilizer (yield 8.86 t ha −1 ) increased yields by 17% and 32% compared to the first rate and non-fertilized treatments, respectively. Weeds infestations (weeds m −2 ) under conventional tillage was considerably lower (7) compared to reduced (39) and zero-tillage (46).

Decreased incidence of disease caused by Sclerotinia sclerotiorum and improved plant vigor of oilseed rape with Bacillus subtilis Tu-100

Sclerotinia sclerotiorum causes serious yield losses in oilseed crops worldwide. Bacillus subtilis Tu-100 significantly reduced (P< or =0.05) the incidence of disease caused by S. sclerotiorum on oilseed rape at harvest in two trials conducted in fields artificially infested with this pathogen. Mean plant dry weight was significantly greater (P< or =0.05) and mean plant length was significantly greater (P< or =0.07) at the seven-true-leaf stage with the Tu-100 treatment than with the control. Mean seed yield per 120 plants at harvest was significantly greater (P< or =0.05) in the second field trial with treatments containing isolate Tu-100. B. subtilis Tu-100 also promoted the growth of hydroponically grown oilseed rape. Plants were approximately 15% greater in dry weight (P< or =0.0001) and 6% greater in length (P< or =0.0025) when grown in the presence of isolate Tu-100 in Hoagland's solution, compared with the noninoculated control. In gnotobiotic studies, the lacZ-tagged strain B. subtilis Tu-100(pUC18) was detected within all roots of oilseed rape. Isolate Tu-100 did not persist in the ectorhizosphere of oilseed rape. Populations of this isolate decreased from 8.5x10(8) colony-forming units (CFU) per seed to approximately 10(2) CFU in the plant ectorhizosphere within 30 days of sowing in autoclaved soil.

Oospores associated with tomato seed may lead to seedborne transmission ofPhytophthora infestans

Tomato fruits at the green mature stage were inoculated with a mixed sporangial suspension of A1 and A2 isolates ofPhytophthora infestans. Other fruits were inoculated with either A1 or A2 sporangia. Seeds were extracted from the blighted fruits and sown in soil or on agar media to test for the transmission of late blight to the emerging seedlings. Only 23 (0.09%) of approximately 25,000 seedlings developed symptoms. All blighted seedlings originated from fruits inoculated with mixed A1 + A2 sporangia. Isolates ofP. infestans recovered from the emerging blighted seedlings were seemingly of oosporic origin, as they differed phenotypically (mating type, virulence, sensitivity to metalaxyl) from the parent isolates used to inoculate the fruits. The results suggest that transmission ofP. infestans might occur by seeds extracted from fruits carrying oospores and less probably by seeds extracted from fruits having no oospores.

The effectiveness of industrial by-products to stop phosphorous loss from a Pallic soil

A study was conducted of the effectiveness of applying various rates (0–50 g/kg) of fly and bottom ash (&lt;2 mm and 2–4 mm) from a coal-fired power plant, and melter (AP10B and PAP5) and basic (KOBM) slags from a steel-manufacturing plant on mitigating phosphorus (P) loss from a Pallic soil sown to pasture. Measurements were made of soil pH, Olsen P, and H2O-P (as a measure of P loss in overland flow), and soluble P and contaminants (B, As, Cd, Pb, Se) from a weekly leaching regime for 9 weeks. Results shows that H2O-P had decreased up to 40% in soils treated at the greatest rate of melter slag (50 g/kg), and increased in KOBM and fly ash treated soils. The effect on Olsen P relative to H2O-P was much less in metler slag and bottom ash treated soils than soils treated with fly ash or KOBM slag. The fly ash was considered unsuitable for the mitigation of P loss from soils due to B toxicity to plants, while KOBM is also unsuitable due to a liming effect and the increase in soluble P loss. At the rates applied, no treated soil leached toxic metals (As, Cd, Hg, or Se) above current guidelines. In contrast, the incorporation of melter slag and bottom ash is considered an effective P loss mitigation strategy.

Viability of holm and cork oak seedlings from acorns sown in soils naturally infected with Phytophthora cinnamomi

SummaryThe emergence and survival of pregerminated holm oak (Quercus ilex) and cork oak (Quercus suber) acorns from two ecologically different dehesas (Mediterranean open woodlands) were studied in two soils from these stands naturally infected with Phytophthora cinnamomi, and in the same soils previously sterilized in the autoclave. Phytophthora cinnamomi was consistently isolated from the radicles of all unemerged and all emerged but dead seedlings from the unsterilized substrates. Seedlings of holm oak were more susceptible to P. cinnamomi than those of cork oak. Mortality of holm oak seedlings was significantly different depending only on soil treatment (sterilized or unsterilized), and it was 100% in unsterilized soils, independent of acorn provenance and soil origin. Mortality of cork oak seedlings was significantly different depending on the acorn origin and soil treatment, and on the interactions acorn origin × soil origin and soil origin × soil treatment. The demonstrated high susceptibility of holm and cork oak young seedlings to P. cinnamomi could be a limiting factor in Mediterranean open woodlands (dehesas) not only in natural regeneration processes but also when reforestation by direct sowing is implemented.

The Canadian Phytopathological Society Annual Meeting, Waterton Lakes National Park, Alberta, 2002

The Canadian Phytopathological Society Annual Meeting, Waterton Lakes National Park, Alberta, 2002

Nitrous oxide emissions from kharif and rabi legumes grown on an alluvial soil

Nitrous oxide (N2O) emissions were monitored for a period of 60 days in a pot culture study, from two kharif (June–September) and two rabi (October–March) season legumes, which were grown on a Typic Ustochrept, alluvial sandy loam soil. Black gram (Vigna mungo L. Hepper), var. T-9, and soybean (Glycine max L. Merril), var. Punjab 1, were taken up in kharif season whereas lentil (Lens esculenta Moench), var. JLS-1, and Bengal gram (Cicer arietinum L.), var. BGD-86, were grown in rabi season. All the crops were grown with and without urea and one pot (containing soil but with no fertilizer or crop) was used as a control. Nitrous oxide emissions were significantly higher in unfertilized cropped soil than in the control, while the addition of urea to the crops further increased the emissions. Significant emissions occurred during third and seventh week after sowing for all the treatments in both kharif and rabi seasons. In kharif, soil cropped with soybean had higher total N2O-N emission than soil sown with black gram both under fertilized and unfertilized conditions; while in rabi, lentil had a higher total N2O-N emission than Bengal gram under both fertilized and unfertilized conditions. In kharif, total N2O-N emissions ranged from 0.53 (control) to 3.84 kg ha–1 (soybean+urea), while in rabi it ranged from 0.45 (control) to 3.06 kg ha–1 (lentil+urea). Higher N2O-N emissions in kharif than in rabi was probably due to the favorable effect of temperature on nitrification and denitrification in the former season. The results of the study indicated that legume crops may lead to an increase in N2O formation and emission from soils, the extent of which varies from crop to crop.

The morphological variability within a population of coffee somatic embryos produced in a bioreactor affects the regeneration and the development of plants in the nursery

A 1-liter bioreactor was used to obtain approximatively 800 Coffea arabica somatic embryos, 86% of which reached the `germinated' stage but with morphological heterogeneity. The population was sub-divided into three categories according to cotyledon area: 'small', 'medium' and 'large', that amounted to 32%, 36% and 4.5%, respectively. The effect of embryo morphology on plantlet conversion after direct sowing in soil and on plant development in the nursery was investigated. Somatic embryos with large cotyledons had only a 25% plantlet conversion rate, whereas somatic embryos with small to medium-sized cotyledons had conversion rates of 47% and 63%, respectively. The vigour of the aerial and root systems of regenerated plantlets at the end of the plant conversion stage was also affected as the embryos with small, medium and large cotyledon mostly regenerated small plantlets (0.5–1.5 cm), medium plantlets (1.5–2.5 cm) and large plantlets (2.5–5 cm), respectively. When transplanted in plastic bags, these 3 populations of plantlets exhibited distinct development rates. They had an initial slow growth phase, which was much longer for the small plantlets, followed by a rapid growth phase. After 40 weeks in the nursery, an analysis of the growth parameters of aerial and radical systems showed that the vigour of the plants was strongly related to the vigour of the plantlets transplanted. The heterogeneity of somatic embryos in the bioreactor affected both the plant conversion efficiency in soil and the plant growth in nursery, where it mainly resulted in retarded growth, primarily in plantlets derived from the somatic embryos with small cotyledons.